Field
The technology described herein relates to micromachined ultrasonic transducers and related apparatus and methods.
Related Art
Capacitive Micromachined Ultrasonic Transducers (CMUTs) are known devices that include a membrane above a micromachined cavity. The membrane may be used to transduce an acoustic signal into an electric signal, or vice versa. Thus, CMUTs can operate as ultrasonic transducers.
Two types of processes can be used to fabricate CMUTs. Sacrificial layer processes form the membrane of the CMUT on a substrate above a sacrificial layer which is then removed to form the cavity of the CMUT beneath the membrane. Wafer bonding processes bond two wafers together to form a cavity with a membrane.